A few simple measures can save you from exorbitant charges and much mental anguish. The Greek Agency for the Prevention of Telecommunication Fraud has some advice: Block the line (call 134 for information) if there are people in the house (children, household help) with access to the telephone who might be tempted to make expensive calls. It is also a good idea to block the line when you are likely to be absent for some time. Beware of illegal diversions of the line. If you pick up the receiver and you hear a different tone than usual, someone may have diverted your line. One way of checking is to call another number, such as your own mobile. If someone has diverted your line, he or she can make international calls at your expense. If you have a private telephone center, beware of hackers. Call the manufacturers and deactivate the DISA (or the telephone mail service) if you do not need it. Ask for a list of outgoing and incoming calls, and pay particular attention to calls made at night, on weekends and to countries abroad. *Be careful about locking the central OTE meters in your apartment building. Check your itemized account so you know what you are being charged for. If you hear an unusual sound (a squeak on the line while you are talking, or interruptions) call OTE immediately. Replace any old cordless phones with the new DECT models. Keep track of your mobile phone. Don’t lend it to anyone, don’t leave it lying around. Keep an eye on it. Check the validity of time cards before you buy them. Don’t buy them from street vendors. Be careful who you give your particulars or documents to, such as identity cards and electricity bills. They can be used without your knowledge to start up mobile telephone accounts. Don’t download software from unreliable sources on the Internet, particularly pornographic sites. Use safety programs on your computer and disconnect the modem from the telephone line after use.